html,body{
    margin: 0;
}

li{
    list-style-type: none;
    /* display: inline; */
}

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.header{
    width: 90vw;
    display: flex;
    margin-top: 30px;
    margin-left: 10vw;
}


.changeBackground{
    width: 60px;
    height: 60px;
    background-color:rgba(255, 255, 255, .6);
    backdrop-filter: blur(4px);
    box-shadow:  0 0 20px #7cc2e4;
    border-radius: 50%;
    /* 调字体 */
    text-align: center;
    line-height: 60px;
    font-family: myFont1;
    text-decoration: none;
    font-size:20px ;
    color: #949494;
    border: 2px solid rgba(255, 255, 255, 0.3);
}




/* 更改链接文字 */
.header li a{
    font-family: myFont1;
    text-decoration: none;
    font-size:20px ;
    color: #949494;
}


/* 设置可见导航条 */
.header .header_ul{
    width: 75%;
    height: 60px;
    line-height: 60px;
    margin-left: 3vw;
    background-color:rgba(255, 255, 255, .6);
    backdrop-filter: blur(4px);
        display: flex;
    justify-content: space-around;
    box-shadow:  0 0 20px #7cc2e4;
    border-radius: 10px;

}

/* 设置一级导航的大小颜色*/
.header .header_ul>li{
    display:block;
    width: 20%; 
    text-align: center; 
    transition: 0.2s;
}

/* 改变被选框颜色*/
.header .header_ul>li:hover{
    background-color: #ececec;
    /* box-shadow:  0 0 20px #7cc2e4; */
}

/* 鼠标移入下拉框显示*/
.header .header_ul>li:hover ul{
    display: block;
}



/* 设置下拉框样式 */
.header .header_ul li>ul{
    width: 100%;
    background-color:white;
    display: none;
}

/* 设置移动条 */
 .header_ul .nav-box{
    position: absolute;
    bottom: 0;
    left: 0;
    /* 如果导航栏就六个导航，那么每个导航的宽度都是整个导航
    的六分之一 */
    width: calc(208px);
    height: 10px;
    border-radius: 2px;
    transition: .5s;
}


.header .header_ul>li:nth-child(1):hover~.nav-box{
    left: calc(25px);
    background-color: rgb(250, 190, 250);
}
.header .header_ul>li:nth-child(2):hover~.nav-box{
    left: calc(100% / 4 *1 + 25px);
    background-color: rgb(250, 190, 250);
}
.header .header_ul>li:nth-child(3):hover~.nav-box{
    left: calc(100% / 4 *2 + 25px);
    background-color: rgb(250, 190, 250);
}
.header .header_ul>li:nth-child(4):hover~.nav-box{
    left: calc(100% / 4 *3 + 25px);
    background-color: rgb(250, 190, 250);
}










.white{
    background: url(./pexels-denis-linine-714256.jpg) fixed no-repeat;
}

.black{
    background: url(./pexels-pixabay-358528.jpg) fixed no-repeat;
}


.container{
    width: 100vw;
    height: 100vh;
    display: flex;
    /* align-items: center; */
    justify-content: center;
    /* background-size:100% 100% */
    background-size: cover;

}

/*

.login-form{
    width: 25vw;
    height: 20vh;
    display: flex;
    flex-direction: column;
    padding: 40px;
    text-align: center;
    position: relative;
    z-index: 100;
    background: inherit;
    border-radius: 18px;
    overflow: hidden;
}

.login-form::before{
    content: "";
    width: calc(100% + 20px);
    height: calc(100% + 20px );
    position: absolute;
    top: -10px;
    left: -10px;
    overflow: hidden;
     background: inherit;
     box-shadow: inset 0 0 0 200px rgba(255, 255, 255, 0.25);
    filter: blur(5px);
    z-index: -1; 
}

.login-form h2{
    font-size: 19px;
    font-size: 400;
}

.login-form input,
.login-form button{
    margin: 7px;
    height: 30px;
    border: none;
    background-color: rgba(247, 247, 249, 0.2);
    border-radius: 4px;
    padding: 0 14px;
    color: rgb(93, 101, 141);
}

.login-form button:focus,
.login-form input:focus{
    outline: 0;
}

.login-form button{
    margin-top: 10px;
    background-color:rgba(49, 49, 196, 0.2);
    color: white;
}

.login-form button:hover{
    background-color: rgba(15, 15, 66, 0.2);
    color: rgb(43, 23, 65);
} */